Noiseblocker NB-BlackSilent Fan PM-1 40mm x 20mm Ultra Silent Fan, 2800rpm, 3 pin, 13.9 dBA, 4.2 CFM Noiseblocker NB-BlackSilentPro PM-1 2800rpm Fan speed 13.9 dBA Noise level 4.20 CFM 40mm x 40mm x 20mm